Chaeles e



(No Model.) y

E. BUI-ILL. TELEPHONE SIGNALS.

No. 248,135.1` Patented 001. 1.1, 1881.

LRS. PhowLnhagnpher. wmbingun. D. L

UNITED STATESv PATENT OFFICE.

CHARLES E. BUELL, OF NEW" HAVEN, CONNECTICUT, ASSIGNOR, BY MESNE ASSIGNMENT, TO THE UNITED STATES TELEPHONE MANUFACTURING COMPANY, OF NEW YORK, N. Y.

TELEPHONE-SIGNAL.

SPECIFICATION formingpart of Letters `:Patent No.. 248,135, dated October 11, 1881.

' Appneanon filed Jun@ 14,1881. (No model.)

To all whom t may concern Be it known that I, CHARLES E. BUELL, a citizen of the United States, residing at New Haven, in the county of New Haven and State 5- of Connecticut, have invented certain new and useful Improvements in- Telephone- Signals; and I doA hereby declare the followingto be a full, clear, and exact description ofthe invention, such as will enable others skilled `in the 1o art to which it appertains to make and use the same, reference being had tothe accompanying drawing, and to the letters or figures of refer-l ence marked thereon, which form a part ot' this specification.

15 This invention relates to that class ot individual call telephone-signal systems in which the signal-controlling electro-magnets at the several stations in the same line are diit'erently adjusted, so that no two of said magnets rc- 2o quire the same definite amount ot' tension in an electrical current to operate them;

r The invention constitutes an improvement upon the subject of Letters Patent No. 221,512, granted to me November 11, 1879.

25 The object of this invention is to provide a novel and convenient arrangement of centralstation devices, by means of which, when a given station is called, the signal-controlling magnets which are more delicately adjusted 3o than that at the said station-will be held closedy and prevented temporarily from operating their signals while the desired call is being given..

lt has also in view the enabling of a cheap and simple class of open-circuit bells to be used at 3 5 the several stations.

The accompanying drawing is a diagram illustrating the arrangement of devices at the central station according to my invention, and a subscribers line connected therewith and in- 4o cluding three stations.

The outlying stations are designated by the numerals 1, 2, and 3, and each is provided with a signal-bell, the magnet M of which has a different adjustment from the corresponding mag- 4 5 nets of each ofthe other stations, the more delicately adjusted magnets being successively more remote from the central station. Each line-station is also provided with the usual receivingtelephone, T, transmitter T', and

ground-wire g, with suitable switches for mak- 5c ing the necessary connection for the purpose of communication. I

At the central station a wire, fw, leading from the battery B, has interposed init at intervals three resistances, R' R2 R3. A key, K', is ar- 5 5 ranged to close circuit through all these resistances over a wire, p2, which leads from the keyanvil n to the metallic pivot of a metallic armature-lever, A', which carries athe armature ot' an electro-magnet, A. A key, K2, closes cr- 6o cuit through the resistances It' and R2, over a wire, p', leading to said armature-lever, and a key, K3, closes circuit through only the resistance R' over a wire, p, leading to said arma- Y ture-lever. The circuit of the local battery B', 65 which charges the magnet A, is connected to the armature-lever by a wire, I),-and with a stop, e, by wire b'. A spiral spring, a', draws the armature-lever against said stop to close circuit, which results in the charging ot' the 7o magnet A and its attraction ot' its armature, thus breaking the circuit, and the magnet becomes immediately discharged, so that the spring a' again -acts on the armature-lever to close the circuit, when the same operation is 75 repeated, there being thus caused a rapid vi- 4bratory motion of the armature-lever, which alternately makes contact with the stops c and e'. The latter of these stops is connected with the line, which includes a galvanometer, G. 8o

The key-stops or anvils may be connected directly with the main line instead of through the automatic circuit `breaker, and I donot claim as my invention the arrangement of an automatic circuit-'breaker to be brought into 85 a main circuit by means ot' a key, as that is old and well known.

The call-bell magnet. M at station 3 is made operative by the manipulation ofthe transmitting-key K', which makes and breaks the cir- 9o cuit through all three of the resistances, as before stated. The electro-magnets of stations l and 2, being too highly adjusted-that is,.re quirin g a greater force to move their armatures than the magnet at station 3-do not respond 95 to the force charging the circuit with all the resistances included therein. To make the magnet at station 2 respond, I manipulate key K2, which cuts ott' the resistance R3, and thus increases the force charging the circuit sufticiently to cause the magnet at station 2 to respond, but not sufficiently to make operative the magnet of station 1, which only responds to the manipulation ot' the key K3, which still further adds to the force charging the circuit by cutting oft' both the resistances R2 and R2.

When either of the keys is depressed the current Hows from the battery B, over the key and its connecting-wire, to the vibratory armature-lever A, the vibration of which rapidly makes and breaks the main-line circuit at the stop c', so that as long as any key is depressed the station signal-magnet which it controls will be rapidly charged and discharged, ringing its bell as long as the key is depressed at the central station. \Vl1cn the key K3 is depressed there will be suicient force ot' current on thc line to operate the bell-magnets at all stations, and when the key K2 is depressed there is force sufiicient to operate the bells at both sta-tions 2 and 3, so that it is necessary to provide means for preventing the ringing of the bells of slight adjustment when only the bell ata station where the magnethasa higher adjustmentisdesiredtoberung. Thesemeans are as follows: A wire, m, leads from a point between the resistance R2 and R2 to a spring, l, arranged below the key K3, and immediately below this spring is arranged a stop, i', which is connected by a wire, s, with the linc around the vibratory armature lever. The spring l is so arranged that when the key K3 is depressed an insulated stud, K4, projecting downward from the key, will force said spring into contact with the stop r before the key makes contact with its stop m2. It will thus be seen that when the key K3 is depressed it causes the battery-circuit first to he closed through the resistance R R2 over the wire m, spring l, stop o', and wire s, a suticient force ot current being then uponl the line to cause the. bell-magnets at stations 2 and 3 to attract their armatures. Immediately, however, that the key comes in contact with its stop a2 the battery-circuit is closed through the resistance R over key K3, the stop u2, and wire p to the vibratory armature-lever, and every time said lever makes contact with the stop c the battery-current will flow over said lever tothe line, avoiding the resistance R2; but when the armature-lever breaks contact at the stop c the current follows the completed circuit over resistance R2. In both cases the current has force enough to cause the bell-leversatstations 2 and 3 to be attracted; but it is only when it reaches the lille over the key Kn andthe armature-lever, avoiding the resistance R2, that it is strong enough to operate the bell at station l. As this route is broken by the vibration of the. lever, the bell-magnet at station l will be onlyintermittently charged, and therefore its bell-lever will be caused to vibrate and ring the bell, being alternately moved by the attraction of the cores and force ot' the retractile spring V. The magnets at the other stations hold their arm atures and bell-levers quietall the time key K3 is depressed. When the key K2 is depressed it closes circuit Iirst through all the resistances over wire m', spring l', stop i", and wire s to line, causing the magnet at station 3 to attract its armature and bell-lever, and when the key strikes stop it the route is opened for the current over wire p and the armature lever A', avoiding resistance R3 when the said lever closes, but passing through said resistance when it breaks the line-circuit; in the latter case only holding closed the magnet at station 3, and in the former case operating the bell at station 2 intermittently.

Having now described my invention and explained the operation thereof, what I claim 1s- 1. The combination, with a mainelectrc line, ot' two or more electro-magnets of different construction or different adjustment arranged in said line, devices for varying the resistance ofthe circuit to correspond to the adjustment ot' said magnets, respectively, circuit-closers for closing the circuit through said resistancevarying devices to correspond to the adjustment of said magnets, as desired, and devices operated by said circuit-closers l'orclosingand holding closed the magnets ot' more delicate adjustment, while an operative current over the line is caused to reach and actuate a magnet of higher adjustment.

2. The combination, with a main telegraph or telephone line having a series of outlying stations provided, respectively, with bell-controlling magnets of different adjustments, and a central ofce provided with circuit-closers for sending currents of variable tension over said line, of devices operated by said circuitclosers l'or sending a current to a more delicately adj usted magnetimmediately in advance of and retaining it upon the line while sending a current to operate a magnet of higher adjustment, substantially as described.

ln testimony whereof I aix my signature in presence ot' two witnesses.

CHARLES E. BUELL.

\Vitnesses:

GEORGE W. Cov, W. B. HALE.

IOO 

